As known, torsional vibrations and cyclic irregularities which are introduced by the crankshaft of an internal combustion engine into its auxiliary unit belt drive can be compensated by belt pulley decouplers, usually designated as decouplers in English, and typically configured as generator belt pulleys. The wrap-around band serves as a one-way clutch which, in the engaged state transmits the drive torque from the belt pulley to the hub, and the elasticity of the decoupler spring connected in series with the decoupler spring smooths the cyclic irregularities originating in the belt drive. When the rotation of the belt pulley is retarded, the wrap-around band disengages, so that, in reverse, no noteworthy torque can be transmitted from the hub to the belt pulley, so that the inert generator shaft can overrun the belt pulley.
DE 10 2009 052 611 A1 discloses a belt pulley decoupler in which the wrap-around band is arranged radially on the inside and the decoupler spring configured as a coil torsion spring is arranged radially on the outside.
A generic type of belt pulley decoupler with an exchanged radial arrangement of the wrap-around band and the coil torsion spring with respect to the above arrangement is disclosed for example in U.S. Pat. No. 8,047,920 B2. Based on this, it is the object of the present disclosure to propose a belt pulley decoupler of the type described above with an alternative constructive configuration.